Permafrost Stores a Globally Significant Amount of Mercury

06 Feb 2018 Wiley
175 volte

Changing climate in northern regions is causing permafrost to thaw with major implications for the global mercury (Hg) cycle. We estimated Hg in permafrost regions based on in situ measurements of sediment total mercury (STHg), soil organic carbon (SOC), and the Hg to carbon ratio (RHgC) combined with maps of soil carbon. We measured a median STHg of 43 ± 30 ng Hg g soil−1 and a median RHgC of 1.6 ± 0.9 μg Hg g C−1, consistent with published results of STHg for tundra soils and 11,000 measurements from 4,926 temperate, nonpermafrost sites in North America and Eurasia. We estimate that the Northern Hemisphere permafrost regions contain 1,656 ± 962 Gg Hg, of which 793 ± 461 Gg Hg is frozen in permafrost. Permafrost soils store nearly twice as much Hg as all other soils, the ocean, and the atmosphere combined, and this Hg is vulnerable to release as permafrost thaws over the next century. Existing estimates greatly underestimate Hg in permafrost soils, indicating a need to reevaluate the role of the Arctic regions in the global Hg cycle.

 

Read full article: 

http://onlinelibrary.wiley.com/doi/10.1002/2017GL075571/full

Vota questo articolo
(0 Voti)

Lascia un commento

Assicurati di aver digitato tutte le informazioni richieste, evidenziate da un asterisco (*). Non è consentito codice HTML.

 

Scienzaonline con sottotitolo Sciencenew  - Periodico
Autorizzazioni del Tribunale di Roma – diffusioni:
telematica quotidiana 229/2006 del 08/06/2006
mensile per mezzo stampa 293/2003 del 07/07/2003
Scienceonline, Autorizzazione del Tribunale di Roma 228/2006 del 29/05/06
Pubblicato a Roma – Via A. De Viti de Marco, 50 – Direttore Responsabile Guido Donati

Photo Gallery